The involvement of the finger nails and toe nails in the psoriasis syndrome is widespread. According to literature references, up to 50% of all psoriasis patients also show changes to the nails in addition to the characteristic skin symptoms. The nail changes are found more frequently on the fingers than on the toes and are identified in the order of their frequency by the following symptoms:
Pitting (punctate or irregularly shaped depressions arranged on the surface of the body of the nail in a certain pattern or alternatively irregularly), discoloration of the nail bed, onycholysis (detachment of the body of the nail from the nail bed), subungual keratosis, or anomalies of the body of the nail.
For treatment of the nails affected by psoriasis, the following four methods were used until now, but without sweeping success, in addition to PUVA phototherapy:
One treatment method, the systemic method, consists in administering methotrexate, retinoids or cyclosporin A orally. This necessitates a long-term treatment, which according to experience can lead to intoxication.
Another method consists in injecting intralesional corticosteroids. This method is naturally very painful, so that the patients are only initially ready to cooperate initially, but later refuse treatment.
With a further method of surgically removing the affected nails, good treatment results can indeed be achieved, but intervention is only temporary because within one week after regeneration of the body of the nail psoriasis may return.
A fourth, gentler, method consists in treating the nails locally with specific, antipsoriatic substances such as dithranol, vitamin D analogs, or corticosteroids. In this context, all sorts of treatment methods have been attempted. Thus, in a combined treatment the nails are first treated with solutions of the antipsoriatic substances. Then cream dressings are applied at night. Even this treatment method is naturally very unpleasant and psychologically distressing for the patient. First, the treatment of the nails with solutions is necessary several times daily. Second, the treated nails must be covered with dressings at night.
This leads to the results that the treatment of patients, usually for many months, is often not completed. Patients become disheartened and negligent and thus no therapeutic result materializes. The success of treatment in this method is furthermore adversely affected because the solutions and creams are usually miscible with water or are hydrophilic and can therefore be removed from the nail surface or dissolved out of the nail by washing, bathing and showering and thus consequently then have to be reapplied again. As a result of this, the treatment with these topical agents is ineffective and, moreover, highly uneconomical.
High hopes have therefore been placed in another method, namely in the treatment of the affected nails with a 50:50 mixture of commercially available corticosteroid-containing lotions, creams or ointments with commercially available clear cosmetic varnishes (U.S. Pat. No. 4,250,164). This method, however, although already known for a long time, has not generally found its way into therapy since a satisfactory result from thesexe2x80x94naturally physically unstablexe2x80x94mixtures do not appear, presumably for lack of sufficient bioavailability of the active compound from the solid system present after the drying of the mixture.
Therefore, many cases, in particular the severe cases, have been treated as before using the surgical method described above or using painful intralesional injections or using combined solution and cream therapy.
WO 97/43644 discloses a topical formulation suitable for the treatment of nail psoriasis comprising at least one glucocorticoid, at least one spreading solvent, at least one readily volatile solvent and a film-forming agent. This topical formulation has the disadvantage that a spreading solvent is necessary. This additional spreading solvent increases the price of the formulation and since It is not clear if this spreading solvent is physiologically acceptable, the approval of the formulation becomes more complicated or even impossible.
The invention aims to make available a glucocorticoid-containing formulation which does not have the disadvantages described above or only has them to a minor extent. In particular, the formulation should guarantee a good penetration of the nail by the glucocorticoid and thus a good bioavailability though a water-insoluble film-forming agent is used.
The invention further aims to make available a glucocorticoid formulation, which does guarantee a good penetration of the nail by the glucocorticoid and thus a good bioavailability, comprising no additional spreading or penetration promoting solvent or substance.
The object is achieved by the nail polish according to the invention, comprising one or more glucocorticoids, a physiologically tolerable, preferably readily volatile, solvent or solvent mixture and one or more water-insoluble film-forming agents.
Antipsoriatic glucocorticoids are, for example: alclometasone dipropionate, amcinonide, beclomethasone dipropionate, bendacort, betamethasone benzoate, betamethasone dipropionate, betamethasone valerate, budesonide, chlorquinaldol, clioquinol, clobetasol propionate, clobetasone butyrate, desonide, desoximetasone, dexamethasone, dichlorisone, difiorasone diacetate, diflucortolone valerate, difluprednate, fluazacort, flucinolone acetonide, fluclorolone acetonide, fludroxycortide, flumethasone pivalate, fluocinolone acetonide, fluocinonide, fluocortolone, fluorometholone, flupamesone, fluprednidene, fluprednidene acetate, flurandrenolide, halcinonide, halometasone, hydrocortamate, hydrocortisone butyrate, methylprednisolone aceponate, mometasone furoate, prednicarbate, prednisolone, prednisone, tixocortol, triamcinolone acetonide.
The glucocorticosteroids can be present either as free alcohols or in the form of their esters.
Suitable water-insoluble film-forming agents are, for example, cellulose derivatives such as cellulose nitrate or ethylcellulose or physiologically acceptable polymers such as are customary, for example, in cosmetics. Mention may be made, for example, of poly(vinyl acetate), and partially hydrolyzed poly(vinyl acetate); copolymers of vinyl acetate with acrylic acid or crotonic acid or monoalkyl maleate; ternary copolymers of vinyl acetate with crotonic acid and vinyl neodecanoate, or crotonic acid and vinyl propionate; copolymers of methyl vinyl ether and monoalkyl maleates, and in particular monobutyl maleate; copolymers of fatty acid vinyl esters and acrylic acid or methacrylic acid; copolymers of N-vinylpyrrolidone, methacrylic acid and alkyl methacrylates; copolymers of acrylic acid and methacrylic acid or alkyl acrylates or alkyl methacrylates, in particular containing quaternary ammonium groups; or polymers, copolymers or mixtures comprising ethyl acrylate, methyl methacry ate or trimethylammonioethyl methacrylate chloride or polyvinyl acetals and polyvinyl butyrals, alkyl-substituted poly-N-vinylpyrrolidone, alkyl esters of copolymers of olefins and maleic anhydride, reaction products of colophony with acrylic acid and also benzoins. In the esters, the alkyl radicals are usually short-chain and mostly do not have more than four carbon atoms.
Suitable physiologically tolerable solvents are substances such as hydrocarbons, halogenated hydrocarbons, alcohols, ethers, ketones and esters which are customary in cosmetics, in particular acetate esters of monohydric alcohols such as ethyl acetate and butyl acetate, optionally as a mixture with aromatic hydrocarbons such as toluene and/or alcohols such as ethanol or isopropanol.
As is known, the combination of the solvents is of crucial importance for the drying time, spreading ability, and other important properties of the varnish or of the varnish film. The solvent system preferably consists of an optimal mixture of low-boiling components (solvents having a boiling point up to 100xc2x0 C.) and medium-boiling components (solvents having a boiling point up to 150xc2x0 C.), optionally with a small proportion of high-boiling components (solvents having a boiling point up to 200xc2x0 C.).
Readily volatile solvents are understood as meaning compounds which have a boiling point which is below 80xc2x0 C.
The nail polishes according to the invention can further contain additives customary in cosmetics, such as plasticizers based on phthalate or camphor, colorants or color pigments, pearl luster agents, sedimentation retardants, sulfonamide resins, silicates, aromatic substances, lanolin derivatives, sunscreens such as 2-hydroxy-4-methoxybenzophenone, antimicrobial substances, and substances having keratolytic and/or keratoplastic action, such as ammonium sulfite, esters and salts of thioglycolic acid, urea, allantoin, enzymes, and salicylic acid.
Using the nail polish according to the invention, one can achieve a drastic cure in the treatment of psoriatic nails, the nail usually growing again without deformation. In view of the poor therapeutic experiences until now, this is an extremely important finding.
The nail polish according to the invention is also suitable for prophylactic use against psoriatic nails, a sufficiently high active compound depot being achieved in the nail such that a possible recurrence does not break out.
The content of active compound in the nail polish according to the invention is dependent on the structure of each active compound and thus on its release from the varnish film, its penetration behavior in the nail, and its potency.
In the nail polish according to the invention, (i.e., the solvent-containing use form) the active compound is in general contained in an amount from 0.5 to 20, preferably 2 to 15, percent by weight. The minimum content of active compound in the medicinal nail polishes (i.e., those for treatment) is preferably 8 percent by weight; the nail polishes used for prophylaxis preferably contain 1 to 4 percent by weight of active compound.
Colored or pigmented nail polishes have the-advantage, for example, that the preparation according to the invention can be tailored to the esthetic perception of the patient.
The nail polish is prepared in a customary manner by mixing together the individual components andxe2x80x94if necessaryxe2x80x94further processing tailored to the respective preparation.
The nail polish according to the invention has the following composition: